Mobile fluoroscopy “C-arm” systems are used in radiology departments and operating rooms (ORs) throughout the world. Quite often, the C-arm systems are required to be operated in different locations within a medical facility or different locations in a room. The C-arm systems are steered and maneuvered during transport from one location to another in mostly a “forward” direction. The C-arms are also maneuvered in lateral directions, such as a direction parallel to the OR table during patient imaging. Lateral directions are perpendicular to the “forward” direction.
Moving the C-arm systems laterally is very important in the use of the C-arm system. For example, when a patent is on the imaging table, the patient is in the lateral position because the C-arm is positioned over the patient. To perform a dye-contrast injection and follow the dye-contrast injection as the injected dye moves from the femoral artery down the leg and into peripheral vasculature, the C-arm must be moved accurately and swiftly along lateral directions.
One particular conventional C-arm design attempted to improve lateral movement of the C-arm system by providing limited lateral travel of the C-assembly with a lateral track at the top of the lift column, and locking the main wheels in the forward position. This design did not provide the amount of lateral travel needed for many common C-arm procedures, and compromised the stability of the C-arm system by shifting the weight from side to side over the base.
Most conventional C-arm systems accomplish lateral motion by rotating both main wheels 90 degrees, from the forward orientation to the lateral orientation. More specifically, the main wheels are mounted on the bottom of an undercarriage, and the undercarriage includes a rotating mount on the base. This method for lateral motion has served the industry for more than three decades, using design solutions for wheel rotation that range from a simple foot lever, to a more sophisticated handle-to-wheel rotational drive assembly. The main-wheel apparatus, however, complicates the design solutions for other features.
In particular, the main-wheel rotating undercarriage apparatus limits the size of the main-wheels, and ultimately limits the maximum weight of the C-arm system. The main wheels cannot be of large diameter in order to keep the main wheels from hitting the base while rotating the main wheels. Large main diameter wheels require a wider carriage in order to pivot the main wheels 90 degrees without running into the base of the C-arm system. However, a wider rotating carriage is not possible because the C-arms must be moved through doorways, and conventional C-arm systems are about as wide as possible for typical doorways. The main wheels cannot be of large width in order to reduce friction of the wheels on the floor while rotating the wheels. As a result, C-arm systems that have rotating wheels cannot be designed with a larger diameter main wheels or wider main wheels.
However, large main wheels are helpful, especially when the C-arm system is moved across carpeted floors. Carpeted floors are not uncommon in healthcare facilities, and are becoming increasingly common outside of sterile environments within the healthcare facilities.
Improved ease-of-transport and maneuverability continue to be high on the list of needed improvements. As mobile C-arm systems approach the equivalent functional features and image quality of fixed-room fluoroscopic X-ray systems, (counter to the goal of improved maneuverability), systems are becoming larger and heavier. Higher power X-ray generators, higher capacity X-ray tubes, and flat panel solid state X-ray detectors requiring on-board cooling solutions, all bring the mobile C-arm one step closer to state-of-the-art fixed-room system performance, but also increase the size, and significantly increases the weight. Rotating the main wheels underneath C-arm systems is becoming more and more difficult as the C-arm systems become heavier. The increasing weight of C-arm systems also indicates that moving the C-arm systems across carpeted floors will require larger wheels.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for an apparatus that configures mobile fluoroscopy C-arm systems (or other mobile imaging systems) for lateral movement and yet will accommodate large main wheels while not requiring a greater width of the C-arm system.